铁(Ⅱ)-TAEB-混合表面活性剂显色体系的研究与应用

Study on the Colour System of Iron with (2-Thiazolylazo)-5-Diethylaminobenzoic Acid-Mixed Surfactants

本文研究了在十二烷基硫酸钠(SDS)-Tween-80阴-非混合表面活性剂存在下,Fe(Ⅱ)与2-(2-噻唑偶氮)-5-二乙氨基苯甲酸(TAEB)的高灵敏显色反应.在pH3.8～5.5的HAc=NaAc缓冲介质中,形成稳定的红紫色胶束配合物,最大吸收在波长610nm处,表观摩尔吸光系数ε_(610)值达1.5×10~5,为目前噻唑偶氮胶束光度法测定铁(Ⅱ)的最灵敏方法,应用于地面水、人发和铝合金中微量铁的测定,结果满意.

In the presence of the mixed surfactants sodium lauryl sulfate (SDS) and Tween-80, the highly sensitive colour reaction of 2-(2-thiazolylazo(-5-diethylaminobenzoic acid (TAEB) with iron (Ⅱ) has been studied, In the HAc-NaAc buffer medium at pH3.8 to 5.5 and in the presence of SDS-Tween-80,iron (Ⅱ) reacts with TAEB to form a 1:3 red-violet complexes. Their λmax and apparent molar absor ptivity are respectively 610nm and 1.5×10~5. Beer's law is obeyed in the range of 0 to 0.52 μtg iron perml.This method gives good selectivity and stability and has successfully been applied to the direct determination of trace iron (Ⅱ) in the natural water, tap water, hair and aluminium alloys.